Combination rubber die



May 8, 1945 L.. E. wALToN 2,375,599

COMBINATION RUBBER DI E Filed June 23, 1941 2 Sheets-Sheet l m ww @4' W 4%/ Y Moana/|24 Y May 8, 1945- L. E. wALToN 2,375,599

COMBINATION RUBBER DIE Filed June 25, 1941 2 Sheets-Sheet 2 gwuwvbop EW/5 E WAL TV Patented May 8, 1945 UNITED STATES PATENT OFFICE COMBINATION RUBBER. DIE

Lewis E.` Walton, West Lawn, Pa.

Application June 23, 1941, Serial No. 399,339

6 Claims.

This invention relates to an apparatus for shaping sheet metal andother material, in the nature of a combinationrubber die, and embodies certain modifications of the structure shown in my original application relating to a Combination hydraulic and rubber die, iiled April 15, 1941, Serial Number 388,707.

One of the important objects of this invention is the production of a simple and eilicient die wherein metal parts may be formed by means of a stationary punch mounted on a post or stake working in conjunction with a. rubber bag under pressure or a solid rubber pad under tension.

A further object of this invention is the production of an efficient die having means for regulating the tension on the yieldable shape-forming element.

Other objects of the present invention will appear throughout the following specification and claims.

In the drawings- Figure 1 is a vertical sectional view through the die;

Figure 2 is a fragmentary sectional view illustrating the manner of forming or shaping the metal parts;

Figure 3 is a vertical sectional view. illustrating a modified form of the invention;

Figure 4 is an enlarged sectional view illustrating a modified form of device for connecting the pressure supply line to the flexible pressure bag:

Figure 5 is a vertical sectional view of a further modified form of the invention; 1

Figure 6 is a vertical sectional view through a still further modied form of the invention;

Figure 7 is a vertical sectional view through still another modified form of the invention;

Figures 8 to 13 inclusive, are various views showing l different formations which may be formed by means of specially designed dies.

By referring to the drawings, it will be seen that I5 designates the lower housing of the die which is preferably anchored or secured to a suitable support and is provided with a compartment I6 in which is supported a centrally located-vertically extending stake or post Il. This post I1 is secured to the bottom of the lower housing I5 by means of an anchor screw I8. A poston washer |9 of suitable design is slidably mounted within the compartment I6 and upon the post or stake I l, in the manner shown in Figure 1. A steel piston plate 2|! rests upon the piston washer I9 and the post I1 extends therethrough. A suitable punch or die member 2| is supported by the post I1, in

the manner shown in Figure 1. An upper movable housing 22 is used in association with the lower housing I5 and is mounted upon a ram of a press in a suitable' manner. This uppermovable housing 22 is provided with a compartment 23 which contains a rubber inflatable bag 24. A nest plate 25 is adapted to rest upon the steel piston plate 20 and an armor plate 26 is carried by the plate 25, the edges of the plate 26 being turned downwardly, as at 21. The punch or die member 2| extends through the nest plate 25 and the armor plate 26. A sheet 28, which is the part to be formed, is adapted to rest upon the punch or die member 2| and is adapted to engage the under face of the inflatable bag 24. l

A nipple 29 is carried by the inflatable bag 24 and comprises an externally threaded stem 30 having a hanged lower end 3l which is serrated upon its upper face. A clamping washer 32 is threaded upon the stem 3l) and is also serrated upon its lower face to rmly clamp the inatable bag 24 in engagement with the nipple 29. A retaining sleeve 33 is threaded upon the threaded stem 30 and carries a iiange 34 for overhanging the top face of the upper movable housing 22 and clamping the iiange 34 against the top wall 35 of the compartment 23,. thereby anchoring the nipple in position. The nipple 29 is provided with a port 3l, which port may be closed by a plug 39,`

and the plug 39 may carry a pressure gauge 38, if desired.

The upper movable housing 22 carries a piston 4| which is vertically movable within the compartment 42 of the housing 43, and a threaded plug 44 is threaded into the upper end of the housing 43 for regulating the tension of the spring 45. The spring 45 is interposed between the plug 44 and the piston 4I. The piston 4| is adapted to relieve pressure from the bag 24 when the pressure exceeds the tension of the spring 45 and which spring tension may be regulated by adjusting the plug 44.

A rubber cushion or rubber Dad, or a pad of other iiowable material, as shown in Figure 5, may be substituted for the rubber bag 24 and the nipple stem, clamping washer, retaining sleeve. and other parts connected with the rubber bag, without violating the spirit of the invention.

The compartment I6 communicates with an inlet 46, which inlet 46 communicates with a suitable accumulator 41 for holding liquid or air under pressure. A pressure gauge 48 is carried by the inlet pipe 46 and an automatic relief valve 49 is carried also by this pipe.

The valve 49 is adapted to relieve pressure beyond a maximum amount, and may be adjusted in the conventional manner` to control the pressure. The operation of the die is as follows: The upper housing 22 descends with the ram. of the press, carrying with it the rubber pad or the bag filled with the proper amount of liquid or air.

vlWhen the pady or bag contacts the sheet to be formed, the downward movement produces the initial pressure needed to clamp the entire area u of the sheet to be formed and thus, acting as a pressure pad, prevent the sheet from wrinkling when the forming takes place. As the housing continues its descent, the parts surrounding the punch |9, 20, 25, 26 and 21, are pushed down against the hydraulic pressure within the compartment I6 and the sheet to be formed takes the shape of the die 2|, as shown in Figure 2. The piston 4| and spring 45 provide a means of relieving the pressure within the bag or pad and thereby provide the means of displacing an equivalent area occupied by the die 2| It should be understood that pressure within the compartment I6 will constitute a yieldable support for the piston 20 due to the fact that '.theautomatic relief valve 49 will relieve pressure from the compartment i6 when pressure above the piston 20 exceeds the pressure in the compartment I6. Consequently the piston 20 will be yieldably supported. In Figure 1 the parts are shown with the pressure not completely applied and in actual practice the sheet 28 will be held between the bag 24 and the armor plate 26, pressure being applied in suitable amounts to the compartment I6 and to the bag 24.

In Figure 3, there is shown a modified type of the invention, wherein a housing 50 is illustrated having a compartment in which is mounted an inatable rubber bag 52. This bag carries a nipple 53, which nipple also engages a steel protector plate 54 carried by the top of the bag, the edges of which plate contact the side walls 55 of the compartment 5|. Ihe platten 56 of the press supports a rest plate 51, which rest plate carries a nest plate 58 and the punch or die member 59 extends .through the plates 51 and 58, as shown. The nest plate 58 may be formed of wood, if desired, and the work sheet 60 is adapted to rest upon the punch 59, and is adapted to be engaged by the rubber bag 52. Pressure pins 6| are carried by the punch 59 and are adapted to be en gaged by the conventional pressure pad 62 of the press.

The nipple 53 is illustrated in detail in Figure 4, and this nipple 53 comprises a bottom flange 63 and an upwardly extending threaded stem '64. which stem 64 is provided with a port 65. A clamping washer 66 is carried by the stem 64, and this washer 66 is held in place by a clamping nut 61. In the form shown in Figure 4, the rubber bag 52 is folded back around the aperture 68 of the plate 54, and the flange |53 and washer 66 which are provided with serrated faces, engage the rubber bag, as shown in Figure 4, to rmly clamp the rubber bag adjacent the edges of the aperture 68. The port 65 is adapted to be closed by a plug l65a, which plug 65 may, if desired, carry a gauge 65h. l

In the form shown in Figure 5, the plattenA T0 of the press supports a punch 1| which may be actuated by a pressure plate 12 of the conventional type. The punch 1I is provided with an annular flange 13 which works within a pocket 14 formed in the nest plate 15. A die housing 16 is mounted upon the nest plate 15, and is provided compressible rubber pad 18. The work sheet 19 rests upon the top of the nest plate 'l5 and upon the punch 1|, and this punch 1| may be moved into engagement with the pad 18, thereby causing the work sheet 19 to be formed around the upper end of the punch 1| in the same manner as that shown in Figure 2. A relief plunger 80 is slidably mounted in the upper end ofthe die housing 16, and this plunger 80 is provided with a retaining flange 8| to limit its downward movement. The plunger 80 contacts the rubber pad 18 and this plunger 80 is engaged by a coil spring 82, the tension of which may be regulated by a threaded plug 83 mounted in the internally threaded neck 84. The plunger 80 will provide a regulated means to permit pressure to be releved from the pad 18 as the rubber pad 18 is being compressed by movement of the die member or punch '|I.` As has been noted above, the die can be made to function through a single downward movement of the ram of the press by means of the piston and hydraulic chamber shown Figure l--see parts I6, l1, I8, |9, 46, 41, 48 and seen that 85 designates a punch-carrying section which carries a die or form 86. A cover plate 87 is carried by the section 85, and a rubber or other flexible diaphragm 88 is clamped between the cover 81 and the section 85. A metal sheet or other work sheet 89 to be formed into the desired shape, rests upon the form or die 8'6. An inlet line 99 communicates with the compartment 9| above the diaphragm 88 and suitablel pressure may be fed thereto and controlled in the same manner as described in the other modied forms. An exhaust pipe 92 communicates with the compartment 9| above the diaphragm 88, and this pipe 92 carries a suitable pressure gauge 93 and an exhaust valve 94. As pressure is fed into the compartment 9|, the exible diaphragm 88 will force the sheet 89 around the form 86 in a-manner somewhat similar to that previously described in the other embodiments. y

In Figure '7, there is'shown a still further modied. form'of the invention wherein 95 designates the punch-carrying section which supports a die member 96 within the compartment 91. A cover plate 98 is provided which clamps a flexible diaphragm 99 ,in Aposition within the compartment 91. The beveled guiding blocks |00 are mounted within the section 95 in a position to be engaged by the edges of the plate or sheet |0| which is to be formed around the die member 96. When pressure is admitted through the inlet pipe |02, the sheet |0I will be formed around the die member 96 and the iiexible diaphragm 99 will follow the position shown in dotted lines. Since the edges of the sheet 9| contact the beveled'faces |03 of 60 the blocks |80, the diaphragm will be prevented from curling under the edges of the plate |8I. A suitable outlet pipe |04 is provided similar to the pipe 92 and may also be provided with a suitable gauge and automatic relief valve.

Figures 8 to 13, inclusive, illustrate various forms of dies as examples to indicate the manner in which the metal may be formed around the dies. In forming the type illustrated in Figure 12, two steps are necessary, and after one side has been formed the metal may be inverted and the opposite or reverse folds may be formed in the conventional manner. that it is not desired to limit the particular type of form or die so far as the shape is concerned,A

since various types may be provided without de- By referring particularly to Figure 6, it will be It should be understood an -unlimited number of operations in one con-V tinuous stroke, except the form shown in Figure 12, as explained above. The form shown in Figure 13, which is in the nature of a rail, such as may be used on toy trains and the like, may be easily produced. Also embossing may be provided clue to the natural functions of the hydraulic pressure, and an important feature to bear in mind is the fact that the flat sheet is formed by means of the hydraulic pressure acting upon the flexible diaphragm, bag, or rubber sheets. The pressure when properly applied will keep the metal from wrinkling when the metal is being formed in the desired shape, with the result that the flanges which are formed become actuallythicker inasmuch as the metal may shrink from a larger circumference to a smaller one. It has been found that the metal will form itself around the unusually shaped dies regardless of the shape or size of the die or form which is used.

It should be understood that although only one die member or punch is shown, any number of die members of various shapes may be used in one unit for forming various articles of difierent shapes in one operation, because of the yieldable pressure member which co-operates with the die member or punch. Further, it should be understood that the unit or units illustrated may be used in a punch press, or press of any kind which would be capable of bringing the top and bottom housings together, such for instance. as the housing shown in Figures 1 and 2. Figures 3 and 5 illustrate units for use on a double acting press, although both could be adapted to be used on a single-action press. Figures 1 andv 2 illustrate a structure which can be mounted on any conventional press which will bring the movable housing 22 and the lower housing I5 together. In this way, the necessity of employing a pressure pad, to bring the die to a stamping or forming position and into contact with the material to be formed. is eliminated. In the form shown in Figure 1, the movable housing 22 is adapted to be bolted to the platen of any press. The purpose of this invention is to produce a unit which may be used upon a conventionalv inexpensive typev crank press` instead of the expensive type of press which is equipped with a hydraulic base and pressure pad, such as has been used heretofore and as fs shown in my application Serial Number 388,707, as Well as in the modifications shown herein.

In the form shown in Figures l and 3, pressure is produced by theaction of the upper housing descending. as itis acted upon by the ram of the press. other pressure is forced into the bag (bag 24 and bag 52) through port 31. The port 3l is then closed and the entire shaping function is accomplished by one movement of the punch press. A pressure gaugel 38, if desired, may be carried by the plug 39 which is adapted to close the port 3l.

It should also be understood that in the forms shown in Figures 6 and 7, an inilatable bag, or layers of rubber, may be substituted for the diaphragms 88 and 99, if desired. Furthermore, conventional mechanical means with automatically acting clamps and springs may perform A selected amount of hydraulic or 7 inflatable bag, adjustable the function of the parts I 5, I6, Il, I9, 20, 46, l1, 4I and 49, if desired, without departing from the spirit of the invention. One ofthe important features of the present invention is the compressible member, such as is illustrated, embodyingeither a rubber member. or layers of rubber strips, or a bag containing hydraulic or other pressure against which the sheet to be formed contacts, thereby forming the sheet in the'contour of the die member or punch.

It shoum be understood that certain detaill changes in the construction and arrangement of parts may be employed without departing from -the spirit of the invention so long as suchl changes fall within the scope of the appended claims.

ton-like means slidably mounted upon the die member and adapted to recede into the base, pressure means for resisting inward movement of the piston means into the base, means for automatically relieving pressure from the piston means at a predetermined degree, an inatable bag carried by the movable housing and adaptedv to engage a work sheet contacting with said die member, a means for supplying pressure to the inatable bag, and adjustable pressure-relieving means carried by said movable housing..

2. A die of the class described comprising a base, a movable housing cooperating with the base, a die member anchored upon the hase, piston-like means slidably mounted upon the die member and adapted to recede into the base. pressure means for resisting inward movement of the piston means into the base, means for automatically relieving pressure from the piston means at a predetermined degree, an inflatable bag carried by the movable housing and adapted to engage a work sheet contacting with said die member, a means for supplying pressure to the pressure-relieving means carried by said movable housing, said inflatable bag being formed of rubber, ,a nipple having clamping engagement with the bag, and means for connecting a pressure supply line to the nipple.

3. A die of the class described comprising a base, a movable housing cooperating withthe base, a die member anchored upon the base, piston-like means slidably mounted upon the die member and adapted to recede into the base, pressure means for resisting inward movement of the piston means into the base, means for automatically relieving pressure from the piston means at a predetermined degree, an inflatable bag carried by the movable housing and adapted to engage a work sheet contacting with said die member for initially clamping the work sheet in engagement with the die member, a means for supplying pressure to the inllatable bag, adjustable pressure-relieving means carried [by said movable housing. said adjustable pressure-relieving means comprising a piston member, said movable housing having an aperture for receiving the piston member, the piston member being adapted to contact the inflatable bag, a spring engaging the piston member, and an adjustable plug for threaded engagement with the movable housing for regulating the tension of said spring.

4. A die of the class described comprising a base, a movable housing cooperating with the bag carried by the movable housing and'adapted to engage a work sheet contacting with said die member, a means for supplying pressure to the inflatable bag, adjustable pressurerelieving means carried by said movable housing, said piston-like means comprising a piston washer, a steel piston member, a nest plate, and a protector armor plate carried by the nest plate.

5. A device of the class described comprising al rigid die member, a movable work-supporting member, a flexible shape-forming' member adapted to clamp material in position upon the lrigid die member and said work-supporting member through the entire area of the material and to shape material placed between the members,

means for applying pressure upon the ilexiblel shape-forming member to shape material placed between the members, said movable work-sup porting member being adjacent the die member for supporting Work placed between said die member and said ilexible shape-forming member,

pressure means supporting said movable worksupporting member in a selected position, means for automatically relieving pressure from the work-supporting .member to permit said worksupporting member to move relative' to the die member as the die member and ilexible worksupporting member assume relative shape-forming positions, and an adjustable automatically movable pressure-displacement means respon--V sive to saidxexible shape-forming member and movable in ratio to the iiex of the flexible shapeforming member relative to the die.

6. A die of the class described comprising a base, a movable housing cooperating with the base, a die member anchored uponthe base, piston-like means slidably mounted upon the die member and adapted to recede into the base, pressure means for resisting inward movement of the piston means into the base, means for automatically relieving pressure from the piston means at a predetermined degree, a flexible shapeforming member carried by the movable housing and adapted to engage a work sheet contacting with said die member, a means for supplying pressure to the flexible shape-forming member, and adjustable pressure-relieving means carried by said movable housing.

LEWIS E. WAL'ION. 

